1. Field of the Invention
The invention concerns a unitarily molded toothbrush manufacturable at low cost providing benefits both over known unitarily molded and non-unitarily manufactured traditional toothbrushes.
2. The Related Art
Millions of individuals around the world are too poor to afford a toothbrush. Even within industrialized countries, there exists a significant population for which this purchase is financially difficult.
No frills relatively low cost products are sold which resemble the expensive ones but without great detail in bristle configuration, handle aesthetics and mouthfeel of bristle tufts within the oral cavity. The bristles are neither sculpted into a shape complementary to the teeth nor the handle given any ergonomic feature. Yet virtually all commercial brushes whether low or high priced are produced by separately adding bristles to a head area anterior to the handle. Invariably the bristles are of a different material (e.g. nylon) than the material forming the head or handle. Two-piece construction greatly increases manufacturing costs. Special machinery is necessary to implant bristles into the head area. Unit production is thereby also relatively slow.
In a review of the art, it was found that certain airlines provide their first class passengers with pocket sized disposable toothbrushes. VARIG, the Brazilian airline, distributes on board a toothbrush described in U.S. Pat. No. 4,408,920 (Walther et al.). Bristles and part of the handle reportedly are injection molded together. Materials of construction are enumerated in the patent as being polyethylene, nylon, polyester or polypropylene, with the latter being preferred. Disposable travel brushes represent significant advances in providing low cost hygiene utensils to the general public at an affordable price. Nonetheless, further technical advances are necessary to improve the functional and ergonomic aspects of these products.
An even lower cost low density polyethylene toothbrush is reported in Brazilian Patent 6700603 developed by the University of Sao Paulo, and widely distributed in that country among school age children. Although inexpensively manufacturable, the bristles have a relatively short lifetime, especially when continuously used in a highly vigorous manner against teeth. Deformation and breakage of individual bristles is a significant problem.
A somewhat more sophisticated approach is reported in U.S. Pat. No. 3,302,230 (Poppelmann) which describes a unitarily molded toothbrush fashioned from polyethylene of Melt Index ranging between 1.5 to 5 g/10 min. Improved massage of the gums and better retention of dentifrice is achieved through use of bristles with special polygonal cross-sections. Unfortunately, this patent, like the others does not address the issue of bristle breakage and deformation. Handle ergonomics are also sub-optimal.
Accordingly, it is an object of the present invention to provide a relatively low cost toothbrush manufacturable in a single step and of a unitary construction.
Another object of the present invention is to provide a relatively low cost toothbrush with bristles less prone to breakage or deformation.
Yet another object of the present invention is to provide a relatively low cost toothbrush with bristles that are gentle to the gum yet effective in reaching food debris even in difficultly accessible crevices between teeth.
Still another object of the present invention is to provide a relatively low cost toothbrush with a sufficiently flexible neck to allow bending of the bristle head relative to the handle thereby being ergonomically adjustable to a user's hand pressure.
These and other objects of the present invention will become more readily evident through the following summary and detailed discussion.